C # wlanapi.dll emitir la recepción de la fuerza de la señal

Question

Actualmente estoy tratando de recuperar la potencia de la señal de un punto de acceso inalámbrico que utiliza la llamada WlanQueryInterface wlanapi.dll.

Esta es mi declaración api

    [DllImport("wlanapi.dll", SetLastError = true)]
private static extern UInt32 WlanQueryInterface(IntPtr hClientHandle, ref Guid pInterfaceGuid, WLAN_INTF_OPCODE OpCode, IntPtr pReserved, out Int32 pdwDataSize, ref IntPtr ppData, IntPtr pWlanOpCodeValueType);

El problema es cuando miro a la entrada wlanSignalStrength en la estructura WLAN_ASSOCIATION_ATTRIBUTES se establece en 5400. documentación de Microsoft API dice que debería ser un valor entre 0 - 100.

Esta es mi declaración de la estructura:

    /// <summary>
/// Structure contains association attributes for a connection.
/// </summary>
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
private struct WLAN_ASSOCIATION_ATTRIBUTES
{
    /// <summary>
    /// A DOT11_SSID structure that contains the SSID of the association.
    /// </summary>
    public DOT11_SSID dot11Ssid;
    /// <summary>
    /// A DOT11_BSS_TYPE value that specifies whether the network is infrastructure or ad hoc.
    /// </summary>
    public DOT11_BSS_TYPE dot11BssType;
    /// <summary>
    /// A DOT11_MAC_ADDRESS that contains the BSSID of the association.
    /// </summary>
    public DOT11_MAC_ADDRESS dot11Bssid;
    /// <summary>
    /// A DOT11_PHY_TYPE value that indicates the physical type of the association
    /// </summary>
    public DOT11_PHY_TYPE dot11PhyType;
    /// <summary>
    /// The position of the DOT11_PHY_TYPE value in the structure containing the list of PHY types.
    /// </summary>
    public ulong uDot11PhyIndex;
    /// <summary>
    /// A percentage value that represents the signal quality of the network.
    /// </summary>
    public Int32 wlanSignalQuality;
    /// <summary>
    /// Contains the receiving rate of the association.
    /// </summary>
    public ulong ulRxRate;
    /// <summary>
    /// Contains the transmission rate of the association.
    /// </summary>
    public ulong ulTxRate;
}

Esta es mi llamada a WlanQueryInterface:

    Int32 iDataSize;
    IntPtr ppData = IntPtr.Zero;
    WLAN_CONNECTION_ATTRIBUTES wcaAttributes = new WLAN_CONNECTION_ATTRIBUTES();
    String[] sReturn = new String[4];

    if (WlanQueryInterface(pClientHandle, ref gInterfaceGUID, WLAN_INTF_OPCODE.wlan_intf_opcode_current_connection, IntPtr.Zero, out iDataSize, ref ppData, IntPtr.Zero) == ERROR_SUCCESS)
    {
        wcaAttributes = (WLAN_CONNECTION_ATTRIBUTES)Marshal.PtrToStructure(ppData, typeof(WLAN_CONNECTION_ATTRIBUTES));

        sReturn[0] = wcaAttributes.wlanAssociationAttributes.dot11Ssid.ucSSID;
        sReturn[1] = wcaAttributes.strProfileName;
        sReturn[2] = String.Format("{0:X2}-{1:X2}-{2:X2}-{3:X2}-{4:X2}-{5:X2}", wcaAttributes.wlanAssociationAttributes.dot11Bssid.bOne, wcaAttributes.wlanAssociationAttributes.dot11Bssid.bTwo, wcaAttributes.wlanAssociationAttributes.dot11Bssid.bThree, wcaAttributes.wlanAssociationAttributes.dot11Bssid.bFour, wcaAttributes.wlanAssociationAttributes.dot11Bssid.bFive, wcaAttributes.wlanAssociationAttributes.dot11Bssid.bSix);
        sReturn[3] = wcaAttributes.wlanAssociationAttributes.wlanSignalQuality.ToString(); //This returns 5400 when the actual strength is ~99

        WlanFreeMemory(ppData);

        return sReturn;
    }
    else
    {
        throw new Exception("Unable to get interface connected SSID.");
    }

¿Alguien ve lo que estoy haciendo mal? Gracias de antemano!

Answer 1

Finalmente llegué lo arreglen. Tenía que establecer el LayoutKind para los WLAN_ASSOCIATION_ATTRIBUTES a explícita y establecer el juego de caracteres Unicode.

    [StructLayout(LayoutKind.Explicit, CharSet = CharSet.Unicode)]
private struct WLAN_ASSOCIATION_ATTRIBUTES
{
    /// <summary>
    /// A DOT11_SSID structure that contains the SSID of the association.
    /// </summary>
    [FieldOffset(0)]
    public DOT11_SSID dot11Ssid;
    /// <summary>
    /// A DOT11_BSS_TYPE value that specifies whether the network is infrastructure or ad hoc.
    /// </summary>
    [FieldOffset(0x24)]
    public DOT11_BSS_TYPE dot11BssType;
    /// <summary>
    /// A DOT11_MAC_ADDRESS that contains the BSSID of the association.
    /// </summary>
    [FieldOffset(40)]
    public DOT11_MAC_ADDRESS dot11Bssid;
    /// <summary>
    /// A DOT11_PHY_TYPE value that indicates the physical type of the association
    /// </summary>
    [FieldOffset(0x30)]
    public DOT11_PHY_TYPE dot11PhyType;
    /// <summary>
    /// The position of the DOT11_PHY_TYPE value in the structure containing the list of PHY types.
    /// </summary>
    [FieldOffset(0x34)]
    public ulong uDot11PhyIndex;
    /// <summary>
    /// A percentage value that represents the signal quality of the network.
    /// </summary>
    [FieldOffset(0x38)]
    public Int32 wlanSignalQuality;
    /// <summary>
    /// Contains the receiving rate of the association.
    /// </summary>
    [FieldOffset(60)]
    public ulong ulRxRate;
    /// <summary>
    /// Contains the transmission rate of the association.
    /// </summary>
    [FieldOffset(0x40)]
    public ulong ulTxRate;
}